angular *ngIf- check if array in specific index null

Question

I want to check if array in specific index is not null this is my code:

    *ngIf="routeService?.selectedPlaces?[index]!=null"

'routeService' is service that the component gets in its constractor and 'selectedPlaces' is array in the service. 'index' is property in the component.

I got this error:

    main.ts:13 Error: Template parse errors:
    Parser Error: Conditional expression routeService?.selectedPlaces?[index]!=null requires all 3 
    expressions at the end of the expression [routeService?.selectedPlaces?[index]!=null] in 
    ng:///PlaceAutocompleteFromDBComponent/template.html@5:29 ("-field class="example-full-width">

How can I check it?

Suren Srapyan · Accepted Answer · 2020-04-26 13:27:56Z

3

In Typescript the elvis operator syntax is ?. In the second case, you have used only ?, which is not valid. You need to to use

*ngIf="routeService?.selectedPlaces && routeService.selectedPlaces[index]"

answered Apr 26, 2020 at 13:27

Suren Srapyan

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3 Comments

Martin Parenteau Over a year ago

The safe navigation operator ?. is defined in Angular templates, not in Typescript.

Suren Srapyan Over a year ago

@ConnorsFan Check newer version of typescript - typescriptlang.org/docs/handbook/release-notes/…

Martin Parenteau Over a year ago

Thanks for the info. I wasn't aware of that.

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